A battery cell has been proposed as a clean, efficient and environmentally responsible power source for electric vehicles and various other applications. One type of battery cell is known as the lithium-ion battery. The lithium-ion battery is rechargeable and can be formed into a wide variety of shapes and sizes so as to efficiently fill available space in electric vehicles, cellular phones, and other electronic devices. For example, the battery cell may be prismatic in shape to facilitate a stacking of the battery cells. A plurality of individual battery cells can be provided in a battery pack to provide an amount of power sufficient to operate electric vehicles.
Nartostructured negative electrodes of lithium-ion batteries have a large surface area resulting in a high irreversible capacity loss (IRCL) due to the formation of a solid electrode interface (SEI). To compensate for Lithium loss in an SEI, extra capacity may be packed onto the positive electrode of the battery. However, this approach reduces the energy density of the battery and potentially leads to an undesirable lithium plating on the negative electrode.
To provide more lithium ions (hereinafter Li) to compensate for an SEI (or another lithium-consuming mechanism), additional or supplementary Li may be provided by pre-lithiation of a component of the battery. One method of pre-lithiation includes providing a Li foil on or adjacent an electrode or separator of the battery. Pre-lithiation may also be achieved by spraying stabilized Li particles onto electrodes of the battery. Due to particle size mismatch between Li particles and typical electrode materials, voids of uncoated electrode may exist, thereby leading to non-homogeneity of the electrode, which is disadvantageous for battery performance. Furthermore, thermal energy is formed during this pre-lithiation process, which increases a complexity and a cost of the battery during mass production. Specifically, the spray process requires dry ambient conditions due to the sensitivity of Li to water and oxygen.
Another pre-lithiation method includes applying a thin coat of Li on a separator of the battery by thermal evaporation or a sputtering process. Mass production of a battery having a separator pre-lithiated using either of these techniques is not cost effective, thereby increasing a cost of the battery. Furthermore, these processes also generate a large amount of thermal energy due to the direct contact between Li metal and an electrode, especially in large cells of the battery. Yet another method of pre-lithiation includes pre-lithiation of an electrode by electrochemical deposition. Mass production of a battery having an electrode pre-lithiated using electrochemical deposition is not cost effective due to the use of excessive amounts of electrolyte required, thereby increasing a cost of the battery.
There is a continuing need for a cost-effective lithium-ion battery suitable for mass production having improved energy density, coulombic efficiency, and abuse tolerance which result in an extended life cycle.